Lay flat coated abrasive discs

ABSTRACT

The present invention relates generally to coated abrasive articles that lay flat, in particular coated abrasive discs, as well as methods of making and using said coated abrasive articles.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119(e) to U.S. PatentApplication No. 62/785,934, entitled “LAY FLAT COATED ABRASIVE DISCS,”by Paul S. GOLDSMITH and William C. RICE, filed Dec. 28, 2018, which isassigned to the current assignee hereof and incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to coated abrasive articles thatlay flat, such as coated abrasive discs, as well as methods of makingand using said coated abrasive articles.

BACKGROUND

Abrasive articles, such as coated abrasives, are used in variousindustries to machine work pieces, such as by lapping, grinding, andpolishing. Surface processing using abrasive articles spans a wideindustrial scope from initial coarse material removal to high precisionfinishing and polishing of surfaces at a submicron level.

Effective and efficient abrasion of high performance metal, ceramic, andcermet industrial parts, such as drill bit components and aircraftengine parts, pose numerous processing challenges.

Industries that produce such parts are sensitive to factors thatinfluence operational costs, including the speed at which a surface canbe prepared, the cost of the materials used to prepare that surface, andthe costs associated with the time expended to prepare a surface.

Therefore, there continues to be a demand for improved abrasive productsand methods that can offer enhanced abrasive processing performance,efficiency, and improved surface quality.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 is an illustration of an embodiment of a coated abrasive article(a coated abrasive disc) that lays flat.

FIG. 2 is an illustration of a cross sectional view of the coatedabrasive article embodiment of FIG. 1 and shows an abrasive layerdisposed directly in contact with a layer of polymeric polyethylenecomposition.

FIG. 3 is a flowchart of an embodiment of a method of making a coatedabrasive article that lays flat.

FIG. 4 is an illustration of an abrasive disc embodiment laying flat.

FIG. 5 is an illustration of another abrasive disc embodiment layingflat.

FIG. 6 is a photograph comparing the curvature of a sample abrasive discembodiment 604 and a conventional abrasive disc 602 where the abrasiveside of both abrasive discs faces upward.

FIG. 7 is a photograph comparing the curvature of a sample abrasive discembodiment 704 and a conventional abrasive disc 702 where the backingside of both abrasive discs faces upward.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION

The following description, in combination with the figures, is providedto assist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This discussion is provided to assist in describing theteachings and should not be interpreted as a limitation on the scope orapplicability of the teachings.

The term “averaged,” when referring to a value, is intended to mean anaverage, a geometric mean, or a median value. As used herein, the terms“comprises,” “comprising,” “includes,” “including,” “has,” “having,” orany other variation thereof, are intended to cover a non-exclusiveinclusion. For example, a process, method, article, or apparatus thatcomprises a list of features is not necessarily limited only to thosefeatures but can include other features not expressly listed or inherentto such process, method, article, or apparatus. As used herein, thephrase “consists essentially of” or “consisting essentially of” meansthat the subject that the phrase describes does not include any othercomponents that substantially affect the property of the subject.

Further, unless expressly stated to the contrary, “or” refers to aninclusive-or and not to an exclusive-or. For example, a condition A or Bis satisfied by any one of the following: A is true (or present) and Bis false (or not present), A is false (or not present) and B is true (orpresent), and both A and B are true (or present).

The use of “a” or “an” is employed to describe elements and componentsdescribed herein. This is done merely for convenience and to give ageneral sense of the scope of the invention. This description should beread to include one or at least one and the singular also includes theplural, or vice versa, unless it is clear that it is meant otherwise.

Further, references to values stated in ranges include each and everyvalue within that range. When the terms “about” or “approximately”precede a numerical value, such as when describing a numerical range, itis intended that the exact numerical value is also included. Forexample, a numerical range beginning at “about 25” is intended to alsoinclude a range that begins at exactly 25. Moreover, it will beappreciated that references to values stated as “at least about,”“greater than,” “less than,” or “not greater than” can include a rangeof any minimum or maximum value noted therein.

As used herein, the phrase “average particle diameter” can be referenceto an average, mean, or median particle diameter, also commonly referredto in the art as D50.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent not described herein, many details regarding specific materialsand processing acts are conventional and can be found in textbooks andother sources within the coated abrasive arts.

COATED ABRASIVE ARTICLE

FIG. 1 shows an illustration of a cross section of an embodiment of acoated abrasive article 100. As shown in FIG. 1, the coated abrasivearticle can include an abrasive layer 103 disposed on a backing material101 (also called herein a “backing”). The backing material 101 cancomprise a backing substrate 105 having a first major surface 109 and asecond major surface 107, wherein a layer of a polymeric front coatcomposition 111 (also called herein a “front coat”) is disposed on thefirst major surface 109 of the backing substrate, and wherein a layer ofpolymeric back coat composition 113 (also called herein a “back coat”)is disposed on the second major surface 107 of the backing substrate.The abrasive layer can include a plurality of abrasive particles 117dispersed on or in a layer of polymeric binder composition 115 (alsocalled herein a “make coat”). The layer of polymeric binder composition115 can be disposed in direct contact with the polymeric front coatcomposition 111. A layer of polymeric size coat composition 119 (alsocalled herein a “size coat”) can be disposed over the polymeric bindercomposition 115 and abrasive particles 117. Further, an optional layerof polymeric supersize coat composition (not shown) can be disposed overthe size coat composition 119. In a particular embodiment, the coatedabrasive article 100 may further include a tool attachment layer (notshown) located opposite the abrasive layer and disposed in contact withthe polymeric back coat composition 113.

FIG. 2 shows an illustration of a coated abrasive article 200embodiment. As shown in FIG. 2, the coated abrasive article 200 caninclude a body 201 that, in a particular embodiment, can be generallydisc shaped. Abrasive particles 203 can be disposed on the workingsurface (also called herein the “abrasive surface” or “top surface”) ofthe abrasive article. In such an abrasive disc embodiment, the coatedabrasive article 200 can be configured to be removably engaged with apower sanding tool (not depicted) such as a random orbit sander or othertype of powered disc sander.

FIG. 3 is an illustration of a flowchart of an embodiment of a method300 of making a coated abrasive article having curl resistance and thatlays flat. Step 302 includes disposing a layer of a polymeric front coatcomposition (also called herein a “front coat”) on a first major surfaceof a backing substrate. Step 304 includes disposing a layer of apolymeric back coat composition (also called herein a “back coat”) on asecond major surface of the backing substrate. In an embodiment, step302 and step 304 can be accomplished at the same time. In anotherembodiment, step 302 and step 304 can be accomplished separately. Step306 includes disposing a layer of a polymeric make coat composition(also called herein a “make coat”) on the front coat. Step 308 includesdisposing a plurality of abrasive particles on or in the make coat. Step310 includes disposing a polymeric size coat composition (also calledherein a “size coat”) over the abrasive particles and the make coat toform an abrasive article. The abrasive article can be used as apolishing film, a polishing belt, or converted (i.e., cut) intodifferent shapes, such as discs, sheets, or other shapes. Step 312includes cutting the abrasive article into a plurality of abrasivediscs. Optionally, a tool attachment layer can be disposed on the backcoat.

FIG. 4 is an illustration of an abrasive disc embodiment laying flat. Asused herein, the term “laying flat” means that when an abrasive disc isplaced at rest on a flat surface that the disc has a curvature where theheight (h) of the disc (i.e., the highest point of the disc) is lessthan or equal to 10% of the diameter of the disc. For instance, if adisc has a diameter (D) of 5 inches, the disc will be considered to layflat if the height of the disc is equal to 0.5 inches or less. As shownin FIG. 4, the curvature of the disc is such that the height of thecenter of the disc is elevated, but is less than 10% of the diameter ofthe disc.

FIG. 5 is an illustration of another abrasive disc embodiment layingflat. As shown in FIG. 5, the curvature of the disc is such that thehighest point(s) (i.e., the height) of the disc is located at theelevated edge(s) of the disc, but is less than 10% of the diameter ofthe disc.

FIG. 6 is a photograph showing an oblique downward view comparing thecurvature of a sample abrasive disc embodiment 604 and a conventionalabrasive disc 602. The abrasive surface of each abrasive disc facesupward away from the flat surface upon which the abrasive disc rests.The sample abrasive disc 604 lays flat and has a curvature where theheight of the disc is less than 10% of the diameter of the disc. Thecomparative abrasive disc 602 does not lay flat.

FIG. 7 is a photograph showing an oblique downward view comparing thecurvature of a sample abrasive disc embodiment 704 and a conventionalabrasive disc 702. The back surface (non abrasive surface) of eachabrasive disc faces upward away from the flat surface upon which theabrasive disc rests. The sample abrasive disc 704 lays flat and has acurvature where the height of the disc is less than 10% of the diameterof the disc. The comparative abrasive disc 702 does not lay flat.

BACKING MATERIAL

As previously stated, the backing material 101 (“backing”) comprises abacking substrate 105 having a first major surface 109 (“first side”)and a second major surface 107 (“second side”), wherein a layer of apolymeric front coat composition 111 (also called herein a “front coat”)is disposed on the first major surface 109 of the backing substrate, andwherein a layer of polymeric back coat composition 113 (also calledherein a “back coat”) is disposed on the second major surface 107 of thebacking substrate. In an embodiment, the backing material 101 can bebeneficially flexible but also is resistant to curling and lays flatwhen at rest. The backing material 101 can comprise a proper combinationof desired physical, chemical, mechanical, and/or performance propertiesand/or features to produce advantageous abrasive performance incombination with abrasive particles as described in greater detailherein.

BACKING SUBSTRATE

The backing substrate can comprise a polymeric film, such as polyolefinfilm (e.g., polypropylene including biaxially oriented polypropylene), apolyester film (e.g., polyethylene terephthalate), a polyamide film, ora cellulose ester film; a metal foil; a mesh; a foam (e.g., naturalsponge material or polyurethane foam); a cloth (e.g., cloth made fromfibers or yarns comprising polyester, nylon, silk, cotton, poly-cotton,rayon, or combinations thereof); a paper; a vulcanized paper; avulcanized rubber; a vulcanized fiber; a nonwoven material; acombination thereof. In an embodiment, the polymeric film can be asurface energy modified film, such as a primed film, a corona treatedfilm, a plasma treated film, a chemically treated film, or a combinationthereof. In a specific example, the backing substrate can comprise apolyester film that has been chemically primed and corona treated orplasma treated. Suitable chemical primers can include imide typeprimers, such as polyethylene imine, and the like.

The backing substrate can have a surface energy in a beneficial range.In an embodiment, the surface energy of the film can be not less than 5dyne, such as at least 10 dyne, at least 20 dyne, at least 30 dyne, atleast 40 dyne, at least 45 dyne or at least 50 dyne. In an embodiment,the surface energy can be not greater than 100 dyne, such as not greaterthan 90 dyne, not greater than 80 dyne, not greater than 70 dyne, notgreater than 65 dyne, or not greater than 60 dyne. The amount of surfaceenergy can be within a range comprising any pair of the previous upperand lower limits. In an embodiment, the polymeric film can have anamount of surface energy not less than 5 dyne to not greater than 100dyne, such as 20 dyne to 90 dyne, such as 30 dyne to 80 dyne, such as 40dyne to 70 dyne, or 50 dyne to 60 dyne.

The backing substrate can have a thickness in a beneficial range. In anembodiment, the thickness of the film can be not less than 1 mil, suchas at least 2 mil, at least 2.5 mil, at least 3 mil, at least 3.5 mil,at least 4 mil, or at least 4.5 mil. In an embodiment, the thickness canbe not greater than 9 mil, such as not greater than 8 mil, not greaterthan 7.5 mil, not greater than 7 mil, not greater than 6.5 mil, or notgreater than 6 mil. The amount of thickness can be within a rangecomprising any pair of the previous upper and lower limits. In anembodiment, the polymeric film can have an amount of thickness not lessthan 1 mil to not greater than 9 mil, such as 2 mil to 8 mil, such as2.5 mil to 7.5 mil, such as 3 mil to 7 mil, or 50 mil to 60 mil.

FRONT COAT

In an embodiment, a layer of a polymeric front coat composition 111 (a“front coat”) is disposed on the first major surface 109 of the backingsubstrate. In an embodiment, the polymeric front coat composition cancomprise a polyethylene composition. The polyethylene composition cancomprise a low density polyethylene (LDPE), a linear low-densitypolyethylene (LLDPE), a high-density polyethylene (HDPE), amedium-density polyethylene (MDPE), or an ultra-high-molecular-weightpolyethylene (UHMWPE). In a specific embodiment, the polymeric frontcoat composition comprises a low density polyethylene.

BACK COAT

In an embodiment, a layer of polymeric back coat composition 113 (a“back coat”) is disposed on the second major surface 107 of the backingsubstrate. In an embodiment, the polymeric back coat composition cancomprise an acrylate composition. The acrylate composition can comprisean ethyl acrylate, an ethylene acrylate, an ethylene-ethyl acrylate(EEA), a methyl acrylate, an ethylene methyl acrylate (EMA) copolymer, abutyl acrylate, a copolymer of ethylene and butyl acrylate (EBA), anethylene acrylic ester terpolymer (i.e., a terpolymer of ethylene,acrylic ester, and maleic anhydride), or a combination thereof. In aspecific embodiment, the back coat composition comprises a mixture of 1)a copolymer of ethylene and butyl acrylate (EBA), and 2) an ethyleneacrylic ester terpolymer (i.e., a terpolymer of ethylene, acrylic ester,and maleic anhydride).

ABRASIVE LAYER

In an embodiment, the abrasive layer can include a plurality of abrasiveparticles 117 dispersed on or in a layer of polymeric binder 115 (“makecoat”). In an embodiment, the abrasive particles can be blended togetherwith the polymeric binder to form an abrasive slurry wherein theabrasive particles are dispersed throughout the binder formulation.Alternatively, the polymeric binder composition can be coated onto thebacking material and the abrasive particles then applied over the bindercomposition. Optionally, patterns can be formed in the abrasive layer bymolding, pressing, or tooling of the abrasive layer.

ABRASIVE PARTICLES

Abrasive particles can include alumina, silicon carbide, silica, ceria,and harder, high performance superabrasive particles such as cubic boronnitride and diamond. The abrasive particles can be essentially singlephase inorganic materials, mixed phase materials, or combinationsthereof. Additionally, the abrasive particles can include compositeparticulate materials, such as aggregates, which can be formed throughslurry processing pathways that include removal of the liquid carrierthrough volatilization or evaporation, leaving behind unfired (“green”)aggregates, that can optionally undergo high temperature treatment(i.e., firing, sintering) to form usable, fired aggregates. Further, theabrasive layer can include engineered abrasives includingmacrostructures and particular three-dimensional structures.

The abrasive particles can be formed of any one of or a combination ofabrasive particles, including silica, alumina (ceramic, fused, orsintered), zirconia, zirconia/alumina oxides, silicon carbide, garnet,diamond, cubic boron nitride, silicon nitride, ceria, titanium dioxide,titanium diboride, boron carbide, tin oxide, tungsten carbide, titaniumcarbide, iron oxide, chromia, flint, emery. For example, the abrasiveparticles can be selected from a group consisting of silica, alumina,zirconia, silicon carbide, silicon nitride, boron nitride, garnet,diamond, co-fused alumina zirconia, ceria, titanium diboride, boroncarbide, flint, emery, alumina nitride, and a blend thereof. Particularembodiments have been created by use of abrasive particles comprised ofdiamond.

In an embodiment, the abrasive particles can be diamond particles (alsoreferred to herein as “diamonds”), cubic boron nitride particles, orcombinations thereof. In an embodiment, the abrasive particles comprisediamonds. The diamonds can be monocrystalline, polycrystalline, or acombination thereof. The diamonds can be natural diamonds, syntheticdiamonds, metal coated diamonds, resin coated diamonds, or combinationsthereof. The abrasive particles can be loose diamonds, diamondagglomerates, diamond aggregates, or a combination thereof.

In specific embodiments, superabrasive particles include cubic boronnitride and diamond particles. These superabrasive particles can benatural (e.g. natural diamond) or synthetic (e.g. cubic boron nitrideand synthetic diamond) products. The superabrasive particles may have ablocky shape associated with them or alternatively, a needle-like shape.The superabrasive particles may be surface coated or not surface coated.In an embodiment, a blend of superabrasive particles and conventionalabrasive particles (e.g. alumina, silicon carbide, ceria, and silica)can be used.

The abrasive particles can have a particular shape, such as a rod, atriangle, a pyramid, a cone, a solid sphere, a hollow sphere, or thelike. Alternatively, the abrasive particles can be randomly shaped.

The abrasive particles can be in a beneficial size range, conform to abeneficial size distribution, or a combination thereof. In anembodiment, the abrasive particles can have an average particle size ofnot less than 1 micron, such as at least 2 micron, at least 3 micron, atleast 5 micron, at least 10 micron, at least 15 micron, at least 20micron, or at least 25 micron. In an embodiment, the average particlesize can be not greater than 500 micron, such as not greater than 400micron, not greater than 300 micron, not greater than 200 micron, notgreater than 150 micron, or not greater than 125 micron. The averageparticle size can be within a range comprising any pair of the previousupper and lower limits. In an embodiment, the abrasive particles canhave an average particle size not less than 5 micron to not greater than250 micron, such as 10 micron to 200 micron, such as 15 micron to 150micron, such as 20 micron to 125 micron.

BINDER COMPOSITION—MAKE COAT OR SLURRY COAT

As stated previously, a layer of polymeric binder composition 115 can bedisposed in direct contact with the polymeric front coat composition111. In a particular aspect, the polymeric binder composition 115 can becomprised of a single polymer or a blend of polymers.

The binder composition can be formed from an epoxy composition, anacrylic composition, a phenolic composition, a polyurethane composition,a urea formaldehyde composition, a polysiloxane composition, orcombinations thereof. In addition, the binder composition can includeactive filler particles, additives, or a combination thereof, asdescribed herein.

The binder composition generally includes a polymer matrix, which bindsabrasive particles to the backing or to a compliant coat, if such acompliant coat is present. Typically, the binder composition is formedof cured binder composition. In an embodiment, the binder compositionincludes a polymer component and a dispersed phase.

The binder composition can include one or more reaction constituents orpolymer constituents for the preparation of a polymer. A polymerconstituent can include a monomeric molecule, a polymeric molecule, or acombination thereof. The binder composition can further comprisecomponents selected from the group consisting of solvents, plasticizers,chain transfer agents, catalysts, stabilizers, dispersants, curingagents, reaction mediators and agents for influencing the fluidity ofthe dispersion.

The polymer constituents can form thermoplastics or thermosets. By wayof example, the polymer constituents can include monomers and resins forthe formation of polyurethane, polyurea, polymerized epoxy, polyester,polyimide, polysiloxanes (silicones), polymerized alkyd,styrene-butadiene rubber, acrylonitrile-butadiene rubber, polybutadiene,or, in general, reactive resins for the production of thermosetpolymers. Another example includes an acrylate or a methacrylate polymerconstituent. The precursor polymer constituents are typically curableorganic material (i.e., a polymer monomer or material capable ofpolymerizing or crosslinking upon exposure to heat or other sources ofenergy, such as electron beam, ultraviolet light, visible light, etc.,or with time upon the addition of a chemical catalyst, moisture, orother agent which cause the polymer to cure or polymerize). A precursorpolymer constituent example includes a reactive constituent for theformation of an amino polymer or an aminoplast polymer, such asalkylated urea-formaldehyde polymer, melamine-formaldehyde polymer, andalkylated benzoguanamine-formaldehyde polymer; acrylate polymerincluding acrylate and methacrylate polymer, alkyl acrylate, acrylatedepoxy, acrylated urethane, acrylated polyester, acrylated polyether,vinyl ether, acrylated oil, or acrylated silicone; alkyd polymer such asurethane alkyd polymer; polyester polymer; reactive urethane polymer;phenolic polymer such as resole and novolac polymer; phenolic/latexpolymer; epoxy polymer such as bisphenol epoxy polymer; isocyanate;isocyanurate; polysiloxane polymer including alkylalkoxysilane polymer;or reactive vinyl polymer. The binder composition can include a monomer,an oligomer, a polymer, or a combination thereof. In a particularembodiment, the binder composition includes monomers of at least twotypes of polymers that when cured can crosslink.

In an embodiment, the binder composition can include epoxy constituentsand acrylic constituents that when cured form an epoxy/acrylic hybridpolymer. Alternatively, the binder composition can comprise a butylacrylate polymer. In an embodiment, the binder composition can comprisea cycloaliphatic epoxy resin, a di-acrylate resin, or a combinationthereof. In a specific embodiment, the binder composition can comprise ahydrogenated diphenylolpropane (DPP) epoxy resin, an oxetane resin(4-member cyclic ether), a bisphenol A Epoxy Diacrylate resin(diacrylate ester of a bisphenol A epoxy resin), a propoxylatedneopentyl glycol diacrylate resin, or combinations thereof.

SIZE COAT LAYER

As described above, layer of polymeric size coat composition 119 (a“size coat”) can be disposed over the polymeric binder composition 115and abrasive particles 117. The size coat composition 119 can be thesame as or different from the polymeric binder composition 115 of theabrasive layer 103 (i.e., the size coat composition can be the same asor different than the make coat composition). The size coat compositioncan include one or more fillers, additives, or a combination thereof.

In a specific embodiment, the size coat composition 119 can comprise anepoxy resin, an acrylic resin, an acrylate resin, an epoxy acrylateresin, or a combination thereof. In an embodiment, the size coatcomposition can comprise a reinforcing additive, such as amorphoussilica. In a specific embodiment, the size coat composition can comprisea cycloaliphatic epoxy resin, an epoxide, a diepoxide, a butanediol, atriacrylate, a hexaacrylate, a cyclohexylcarboxylate, or a combinationthereof. In a specific embodiment, the size coat composition cancomprise a silica reinforced cycloaliphatic epoxy resin, an aliphaticepoxidized butanediol, trimethylolpropane triacrylate (TMPTA),dipentaerythritol hexaacrylate (DPHA), (3,4-epoxycyclohexane) methyl3,4-epoxycyclohexylcarboxylate, or a combination thereof.

In a specific embodiment, the size coat composition can include 5 wt %to 45 wt % of a reinforcing filler, such 10 wt % to 35 wt % of areinforcing filler.

SUPERSIZE COAT COMPOSITION

As previously described, the coated abrasive article 100 can optionallycomprise a layer of supersize coat composition (not shown) disposed onthe size coat composition 119. The supersize coat composition can be thesame as or different from the polymeric binder composition 115 of theabrasive layer 103 and can be same as or different than the size coatcomposition 119 disposed thereon. In another aspect, the supersize coatcomposition may comprise an anti-loading agent (such as a stearate, suchas a metal stearate, such as zinc stearate or calcium stearate) or agrinding aid (such as cryolite, potassium borofluorate), or acombination thereof.

ADDITIVES

In a particular aspect, the front coat composition 111, the back coatcomposition 113, the binder composition 115, the size coat composition119, or the supersize coat composition (not shown) can include one ormore additives. Additives can be available in an amount of 0 wt % to 10wt % of any polymer layer (i.e., make coat layer, size coat layer, orsupersize layer). Suitable additives, for example, can include grindingaids, fibers, lubricants, wetting agents, thixotropic materials,surfactants, thickening agents, pigments, dyes, antistatic agents,coupling agents, plasticizers, suspending agents, pH modifiers, adhesionpromoters, lubricants, bactericides, fungicides, flame retardants,degassing agents, anti-dusting agents, dual function materials,initiators, chain transfer agents, stabilizers, dispersants, reactionmediators, colorants, and defoamers. The amounts of these additivematerials can be selected to provide the properties desired. Theseoptional additives can be present in any part of the overall system ofthe coated abrasive product according to embodiments of the presentdisclosure. Suitable grinding aids can be inorganic based; such ashalide salts, for example cryolite, wollastonite, and potassiumfluoroborate; or organic based, such as sodium lauryl sulphate, orchlorinated waxes, such as polyvinyl chloride. In an embodiment, thegrinding aid can be an environmentally sustainable material.

TOOL ATTACHMENT LAYER

The abrasive article can optionally include a tool attachment layer. Ina particular embodiment, the coated abrasive article 100 includes a toolattachment layer (not shown) that can be used to removably engage thecoated abrasive article 100 with a power tool, such as a rotary sander.The tool attachment layer can include an adhesive.

In another aspect, the tool attachment layer can include a mechanicalfastener. For example, the mechanical fastener can include a hookfastener, a loop fastener, or a combination thereof that is configuredto removably engage with a corresponding mechanical fastener on the toolon which the coated abrasive article 100 is intended to be disposedduring abrasive operations.

EMBODIMENTS

Embodiment 1. A coated abrasive article comprising: an abrasive layerdisposed on a backing material; wherein the backing material comprises:a backing substrate having a first side and a second side, and a layerof polymeric polyethylene composition disposed on the first side of thebacking substrate; wherein the abrasive layer is disposed directly incontact with the polymeric polyethylene composition.

Embodiment 2. The coated abrasive article of embodiment 1, wherein thecoated abrasive article lays flat.

Embodiment 3. The coated abrasive article of embodiment 1, wherein thecoated abrasive article has a curvature of not greater than 10% of thediameter of the abrasive article.

Embodiment 4. The coated abrasive article of embodiment 1, wherein theabrasive layer comprises a make coat or a size coat having a Young'smodulus (stiffness) of at least 150 kpsi, such as at least 200 kpsi, atleast 250 kpsi, at least 300 kpsi, at least 350 kpsi, at least 400 kpsi,at least 450 kpsi, or at least 500 kpsi.

Embodiment 5. The coated abrasive article of embodiment 4, wherein theabrasive layer comprises a make coat or a size coat having a Young'smodulus (stiffness) of not greater than 900 kpsi, such as not greaterthan 850 kpsi, not greater than 800 kpsi, not greater than 750 kpsi, notgreater than 700 kpsi, not greater than 650 kpsi, or not greater than600 kpsi.

Embodiment 6. The coated abrasive article of embodiment 1, wherein thepolymeric polyethylene composition comprises low density polyethylene,high density polyethylene, or a combination thereof.

Embodiment 7. The coated abrasive article of embodiment 1, wherein thelayer of polymeric polyethylene composition comprises a thickness of atleast 0.25 mil to not greater than 0.5 mil, such as at least 1 mil tonot greater than 3 mil, or at least 1.5 mil to not greater than 2.5 mil.

Embodiment 8. The coated abrasive article of embodiment 1, furthercomprising a layer of polymeric acrylate composition disposed on asecond side of the backing substrate.

Embodiment 9. The coated abrasive article of embodiment 8, wherein thepolymeric acrylate composition comprises ethyl acrylate, ethyleneacrylate, ethylene-methyl acrylate, ethylene-ethyl acrylate, or acombination thereof.

Embodiment 10. The coated abrasive article of embodiment 8, wherein thelayer of polymeric acrylate composition comprises a thickness of atleast 0.1 mil to not greater than 3 mil, such as at least 0.25 mil tonot greater than 2.5 mil, or at least 0.5 mil to not greater than 2 mil.

Embodiment 11. The coated abrasive article of embodiment 1, wherein thebacking substrate comprises a polymeric film.

Embodiment 12. The coated abrasive article of embodiment 11, wherein thepolymeric film comprises a polyester film.

Embodiment 13. The coated abrasive article of embodiment 11, wherein thepolymeric film comprises polyethylene terephthalate.

Embodiment 14. The coated abrasive article of embodiment 11, wherein thepolymeric film comprises a thickness of at least 1 mil to not greaterthan 10 mil, such as at least 2 mil to not greater than 8 mil, at least3 mil to not greater than 7 mil, or at least 4 mil to not greater than 6mil.

Embodiment 15. The coated abrasive article of embodiment 11, wherein thepolymeric film comprises a surface energy of at least 40 dyne/cm², suchas at least 45 dyne/cm².

Embodiment 16. The coated abrasive article of embodiment 15, wherein thepolymeric film is corona treated.

Embodiment 17. The coated abrasive article of embodiment 1, wherein theabrasive layer comprises a polymeric make coat composition and abrasiveparticles disposed in the make coat composition.

Embodiment 18. The coated abrasive article of embodiment 17, wherein themake coat composition comprises an epoxy acrylate polymer, an epoxymethacrylate polymer, a butyl acrylate polymer, or a combinationthereof.

Embodiment 19. The coated abrasive article of embodiment 17, wherein themake coat composition further comprises a filler.

Embodiment 20. The coated abrasive article of embodiment 17, wherein theabrasive layer further comprises a polymeric size coat compositiondisposed on the make coat composition and abrasive particles.

Embodiment 21. The coated abrasive article of embodiment 17, wherein thesize coat composition comprises an epoxy acrylate polymer, an epoxymethacrylate polymer, a butyl acrylate polymer, or a combinationthereof.

Embodiment 22. The coated abrasive article of embodiment 17, wherein themake coat composition further comprises a filler.

Embodiment 23. The coated abrasive article of embodiment 17, wherein theabrasive particles comprise diamond, cubic boron nitride, or acombination thereof.

Embodiment 24. The coated abrasive article of embodiment 23, wherein theabrasive particles comprise a grit size of 5 microns to 500 microns.

EXAMPLES Example 1.—Sample Coated Abrasive Film Preparation

Sample coated abrasive film was prepared as described herein. In a firststep, a backing material was prepared by applying a front coat and aback coat to a backing substrate. Details of the backing material areprovided below in Table 1. The completed backing material was stored forlater use.

TABLE 1 Backing Material S1 Front Coat Low density polyethylene BackingPolymer film¹, primed², and corona treated³ Substrate Back CoatCopolymer Blend 90-95 wt % ethylene and butyl acrylate copolymer 05-10wt % ethylene acrylic ester terpolymer⁵ ¹Chemically treated PET film, 5mil thick ²Primer—polyethylene imine ³50-60 dyne/cm², both sides⁴Lotryl, Arkema, Inc. ⁵Lotader, Arkema, Inc.

The prepared backing material was then used to make a sample coatedabrasive film as described herein. A make coat was applied to thebacking material wherein the make coat was disposed onto the front coatof the backing material. Abrasive particles were disposed on the makecoat and a size coat was applied over the make coat and abrasiveparticles. Details of the make coat, abrasive particles, and size coatare provided below in Table 2. The completed coated abrasive film wasstored as a jumbo roll for later use.

TABLE 2 Coated Abrasive Film S1 Size Coat UV curable copolymer blend40-65 wt % epoxy resin 3⁹ 10-20 wt % epoxy resin 4¹⁰ 1-10 wt % acrylateresin 2¹¹ 0-5 wt % acrylate resin 3¹² 0-5 wt % epoxy acrylate resin¹³10-20 wt % filler¹⁴ Abrasive Metal bond diamond, 65-75 micron ParticlesMake Coat UV curable copolymer blend 55-75 wt % epoxy resin 1⁶ 05-12 wt% epoxy resin 2⁷ 10-20 wt % oxetane 1-08 wt % acrylate resin⁸⁶Diphenylolpropane (DPP) resin—Eponex ⁷Bisphenol A EpoxyDiacrylate—Ebecryl ⁸Propoxylated neopentyl glycol diacrylate—Sartomer⁹Silica reinforced cycloaliphatic epoxy resin (Nanopox) ¹⁰Aliphaticepoxidized butanediol (Erisyg) ¹¹Trimethylolpropane triacrylate (TMTPA)¹²Dipentaerythritol hexaacrylate (DPHA) ¹³methyl3,4-epoxycyclohexylcarboxylate ¹⁴Amorphous silica

Example 2.—Sample Lay Flat Abrasive Discs

Sample coated abrasive film discs were prepared as described herein.Sample coated abrasive polishing film as prepared above in Example 1 wasobtained from the jumbo roll and converted (i.e., cut) into a pluralityof discs to make sample coated abrasive polishing discs. Surprisingly,even thought the discs were obtained from material near the center ofthe jumbo roll, the discs did not exhibit any significant curling andlaid flat compared to conventional coated abrasive polymer film discs(i.e., when the unused disc was resting on a flat surface, the height ofthe highest point of the disc was less than 10% of the diameter of thedisc, such as even less than 5% of the diameter of the disc. As shown inFIG. 6, the curvature of the sample abrasive disc embodiment 604(abrasive face up) demonstrated that the sample disc was able to lay“flat” as described herein. In contrast, the comparative conventionalabrasive film disc 602 (abrasive face up) had an excessive curvature(excessive curl) and did not lay “flat.” Similarly, as shown in FIG. 7,the curvature of the sample abrasive disc embodiment 704 (backing sideup) and a comparative conventional abrasive film disc 702 (backing sideup) had an excessive curvature (excessive curl) and did not lay “flat.”

In the foregoing, reference to specific embodiments and the connectionsof certain components is illustrative. It will be appreciated thatreference to components as being coupled or connected is intended todisclose either direct connection between said components or indirectconnection through one or more intervening components as will beappreciated to carry out the methods as discussed herein. As such, theabove-disclosed subject matter is to be considered illustrative, and notrestrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Moreover, not all of theactivities described above in the general description or the examplesare required, that a portion of a specific activity cannot be required,and that one or more further activities can be performed in addition tothose described. Still further, the order in which activities are listedis not necessarily the order in which they are performed.

The disclosure is submitted with the understanding that it will not beused to limit the scope or meaning of the claims. In addition, in theforegoing disclosure, certain features that are, for clarity, describedherein in the context of separate embodiments, can also be provided incombination in a single embodiment. Conversely, various features thatare, for brevity, described in the context of a single embodiment, canalso be provided separately or in any subcombination. Still, inventivesubject matter can be directed to less than all features of any of thedisclosed embodiments.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that cancause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

Thus, to the maximum extent allowed by law, the scope of the presentinvention is to be determined by the broadest permissible interpretationof the following claims and their equivalents, and shall not berestricted or limited by the foregoing detailed description.

What is claimed is:
 1. A coated abrasive article comprising: an abrasivelayer disposed on a backing material, wherein the backing materialcomprises: a backing substrate having a first side and a second side;and a layer of polymeric polyethylene composition disposed on the firstside of the backing substrate; wherein the abrasive layer is disposeddirectly in contact with the polymeric polyethylene composition.
 2. Thecoated abrasive article of claim 1, wherein the coated abrasive articlelays flat.
 3. The coated abrasive article of claim 1, wherein the coatedabrasive article has a curvature of not greater than 10% of the diameterof the abrasive article.
 4. The coated abrasive article of claim 1,wherein the abrasive layer comprises a make coat or a size coat having aYoung's modulus (stiffness) of at least 150 kpsi, such as at least 200kpsi, at least 250 kpsi, at least 300 kpsi, at least 350 kpsi, at least400 kpsi, at least 450 kpsi, or at least 500 kpsi.
 5. The coatedabrasive article of claim 4, wherein the abrasive layer comprises a makecoat or a size coat having a Young's modulus (stiffness) of not greaterthan 900 kpsi, such as not greater than 850 kpsi, not greater than 800kpsi, not greater than 750 kpsi, not greater than 700 kpsi, not greaterthan 650 kpsi, or not greater than 600 kpsi.
 6. The coated abrasivearticle of claim 1, wherein the polymeric polyethylene compositioncomprises low density polyethylene, high density polyethylene, or acombination thereof.
 7. The coated abrasive article of claim 1, whereinthe layer of polymeric polyethylene composition comprises a thickness ofat least 0.25 mil to not greater than 0.5 mil, such as at least 1 mil tonot greater than 3 mil, or at least 1.5 mil to not greater than 2.5 mil.8. The coated abrasive article of claim 1, further comprising a layer ofpolymeric acrylate composition disposed on a second side of the backingsubstrate.
 9. The coated abrasive article of claim 8, wherein thepolymeric acrylate composition comprises ethyl acrylate, ethyleneacrylate, ethylene-methyl acrylate, ethylene-ethyl acrylate, or acombination thereof.
 10. The coated abrasive article of claim 8, whereinthe layer of polymeric acrylate composition comprises a thickness of atleast 0.1 mil to not greater than 3 mil, such as at least 0.25 mil tonot greater than 2.5 mil, or at least 0.5 mil to not greater than 2 mil.11. The coated abrasive article of claim 1, wherein the backingsubstrate comprises a polymeric film formed from at least one ofpolyester and polyethylene terephthalate.
 12. The coated abrasivearticle of claim 11, wherein the polymeric film comprises a thickness ofat least 1 mil to not greater than 10 mil, such as at least 2 mil to notgreater than 8 mil, at least 3 mil to not greater than 7 mil, or atleast 4 mil to not greater than 6 mil.
 13. The coated abrasive articleof claim 11, wherein the polymeric film comprises a surface energy of atleast 40 dyne/cm², such as at least 45 dyne/cm².
 14. The coated abrasivearticle of claim 13, wherein the polymeric film is corona treated. 15.The coated abrasive article of claim 1, wherein the abrasive layercomprises a polymeric make coat composition and abrasive particlesdisposed in the make coat composition.
 16. The coated abrasive articleof claim 15, wherein the make coat composition comprises an epoxyacrylate polymer, an epoxy methacrylate polymer, a butyl acrylatepolymer, or a combination thereof.
 17. The coated abrasive article ofclaim 15, wherein the abrasive layer further comprises a polymeric sizecoat composition disposed on the make coat composition and abrasiveparticles.
 18. The coated abrasive article of claim 15, wherein the sizecoat composition comprises an epoxy acrylate polymer, an epoxymethacrylate polymer, a butyl acrylate polymer, or a combinationthereof.
 19. The coated abrasive article of claim 15, wherein theabrasive particles comprise diamond, cubic boron nitride, or acombination thereof.
 20. The coated abrasive article of claim 19,wherein the abrasive particles comprise a grit size of 5 microns to 500microns.